自我引用结构的定义如下：
对于第二种情况：
struct node{
int data1;
int data2;
struct node *ptr;
}obj,*temp;
int main()
{
printf("\n Address of variable data1 in struct is %p",&obj.data1);
printf("\n Address of variable data2 in struct is %p",&obj.data2);
}
输出结果为：
结构体中变量 data1 的地址是 0xd0c7010
结构体中变量 data2 的地址是 0xd0c7018
这意味着 data1 占用了 8 字节的内存，对吗？
但如果我有以下结构体定义：
struct node{
int data1;
int data2;
}obj,*temp;
int main()
{
printf("\n Address of variable data1 in struct is %p",&obj.data1);
printf("\n Address of variable data2 in struct is %p",&obj.data2);
}
输出结果为：
结构体中变量 data1 的地址为 0xd0c6010
结构体中变量 data2 的地址为 0xd0c6014
因此，data1 占用的内存空间为 4 字节，就像整数变量一样，对吗？
但是，在第一种情况下，为什么 data1 占用的内存空间增加了呢？
编辑： 对于第一种情况，输出结果为
Address of variable data1 in struct is 0x600940
Address of variable data2 in struct is 0x600944
The address of ptr is 0x600948
The size of struct is 16
对于第二种情况：
Address of variable data1 in struct is 0x600910
Address of variable data2 in struct is 0x600914
The size of struct is 8
我正在Linux上使用gcc (GCC) 4.1.2运行此代码
上述代码可以正常工作，但下面这个呢？
#include <stdio.h>
#include <stdlib.h>
struct node
{
int data;
struct node *next;
};
// This function prints contents of linked list starting from the given node
void printList(struct node *n)
{
printf("\n The memory location of n is %p ",n);
while (n != NULL)
{
printf(" %d ", n->data);
n = n->next;
printf("\n The memory location of n in while loop is %p ",n);
}
}
int main()
{
struct node* head = NULL;
struct node* second = NULL;
struct node* third = NULL;
// allocate 3 nodes in the heap
head = (struct node*)malloc(sizeof(struct node));
second = (struct node*)malloc(sizeof(struct node));
third = (struct node*)malloc(sizeof(struct node));
head->data = 1; //assign data in first node
head->next = second; // Link first node with the second node
printf("\n The memory address of head->data is %p ",&head->data);
printf("\n The memory address of head->next is %p ",&head->next);
second->data = 2; //assign data to second node
second->next = third;
printf("\n The memory address of second->data is %p ",&second->data);
printf("\n The memory address of second->next is %p ",&second->next);
third->data = 3; //assign data to third node
third->next = NULL;
printf("\n The memory address of third->data is %p ",&third->data);
printf("\n The memory address of third->next is %p ",&third->next);
printList(head);
getchar();
printf("\n");
return 0;
}
O/P是指
The memory address of head->data is 0x215c010
The memory address of head->next is 0x215c018
The memory address of second->data is 0x215c030
The memory address of second->next is 0x215c038
The memory address of third->data is 0x215c050
The memory address of third->next is 0x215c058
The memory location of n is 0x215c010 1
The memory location of n in while loop is 0x215c030 2
The memory location of n in while loop is 0x215c050 3
The memory location of n in while loop is (nil)
为什么现在还有8个字节的差异？ 我正在与其他两个相同的环境下运行此代码。